This gist of this is that the script can't depend on any desktop resource during playback.

If it did then very likely two (or more) of the tests would interact with each other, via the desktop, and you would have "crazy" results.

The sure way to test if your script is load test safe is to run the script with the eValid browser minimized.

If it runs OK when minimized then you know it is load test safe.

As the document describes, you can use Lock/Unlock on scripts that may need to share the desktop, but even with this in place you are creating delays in playback due to the desktop havingto be shared temporally between multiple playback images.

The Lock/Unlock feature works OK, but not having to use that expedient is a big advantage.